Rockwell Automation 8520-MUM 9/Series CNC Mill Operation and Programming Manual Documentation Set - Manual (Page 334)

Coordinate System Offsets
Chapter 11
11-18
When a Set Zero operation is performed the control shifts the current work
coordinate system so that the current tools position is the zero point of the
coordinate system. The axis that set zero is effective in is selected through
PAL (refer to system installers Documentation) or by the current jog axis if
using the {FRONT PANEL} option.
The Set Zero offset is similar to the execution of a G92 X0 Y0 Z0 block,
with one exception. Unlike a G92, the set zero will not cancel a G52
offset. The G52 will remain active and continue to offset the current tool
position in the work coordinate system. When the G52 offset is canceled
later the coordinate system will shift.
The Set Zero offset can be canceled by programming a G92.1 command,
executing a control reset operation, executing an E-STOP reset operation,
or programming an end of program M30 or M02 command.
CAUTION: Set Zero offsets are global. This means that
changing from one coordinate system to another does not cancel
the offset. Do not specify a change in coordinate systems
(G54-G59.3) unless the effects of the offset have been
considered.
Example 11.8
Typical Set Zero Offset Application
Operation Comment
-Manual jog- axes are manually jogged to a location where the operator has deter-
mined that a special operation must be performed.
-Set Zero- operator performs a Set Zero offset to establish the work coordinate
system zero point at the current axis location.
-Run program- a generic special operation program can now be executed from the axis
coordinate position that resulted from the manual jog and Set Zero.
The set zero offset may be performed through an optional switch installed
by the system installer or through the {SET ZERO} softkey as described in
section 2.3 on using the {FRONT PANEL} softkey.
CAUTION: Set Zero offsets are global. This means that
changing from one coordinate system to another does not cancel
the offset. Do not specify a change in coordinate systems
(G54-G59.3) unless the effects of the offset have been
considered.
11.4.3
{SET ZERO} Offset